puka: Software for detection of breaths in strain gauge recordings

This software was first described in: Etzel JA, Johnsen EL, Dickerson JA,
Adolphs R. A program to accurately identify peaks in respiration and EKG
signals for use in psychophysiological research. Psychophysiology41 (s1), S73 (2004).

Please cite the above publication when referencing this material, and also include the standard citation for PhysioNet:

Puka is a
Hawaiian word meaning appear, emerge, or an opening,
and is also the name of a small round shell with a center hole found on some
Hawaiian beaches. It was selected to reflect the exploratory nature of the
experiments which generate the data to be analyzed with this program as well as
the new knowledge that may be gained.

puka, written in Java, uses MATLAB for signal processing and
statistical calculations, and the WFDB
Software Package and ecgpuwave for
EKG peak detection. Puka can also read and write data from a MySQL
database. puka was developed and tested using
Cygwin under MS-Windows,
but puka should be usable on other platforms supported by MATLAB as
well.

puka incorporates a new method of identifying the breaths and pauses
in strain gauge belt recordings. This technique locates the points of maximum
inspiration and expiration for each breath as well as post-inspiratory and
post-expiratory pauses. The authors found that puka correctly locates
normal R waves in EKG signals and breaths in strain gauge belt recordings,
in tests using artificial EKG data, paced respiration recordings from
healthy young subjects, and recordings from neurological patients.